diff --git a/src/main/java/com/interplug/qcast/biz/estimate/EstimateService.java b/src/main/java/com/interplug/qcast/biz/estimate/EstimateService.java
index 02de114a..0e83d64d 100644
--- a/src/main/java/com/interplug/qcast/biz/estimate/EstimateService.java
+++ b/src/main/java/com/interplug/qcast/biz/estimate/EstimateService.java
@@ -1916,14 +1916,15 @@ public class EstimateService {
         //   schDrawingFlg / schWeightFlg(위쪽 분기)로 선택된 부속 시트
         //   (割付図・系統図 / 架台図 / 発電シミュレーション / 重量算出シート 등)는 그대로 유지한다.
         if ("EXCEL2".equals(estimateRequest.getSchDownload())) {
-          // 旧見積書書式: 신 양식 견적서 시트(見積書) 제거 후, 구 양식(見積書.)을 맨 앞으로 이동
+          // 旧見積書書式: 신 양식 견적서 시트(見積書) 제거 후, 구 양식(御見積書)을 맨 앞으로 이동
+          // 2026-06-01 시트명 변경: 見積書. → 御見積書
           safeRemoveSheet(workbook, "見積書");
-          if (workbook.getSheetIndex("見積書.") > 0) {
-            workbook.setSheetOrder("見積書.", 0);
+          if (workbook.getSheetIndex("御見積書") > 0) {
+            workbook.setSheetOrder("御見積書", 0);
           }
         } else {
-          // 신(통상) 견적서 양식: 구 양식 견적서 시트(見積書.)만 제거
-          safeRemoveSheet(workbook, "見積書.");
+          // 신(통상) 견적서 양식: 구 양식 견적서 시트(御見積書)만 제거
+          safeRemoveSheet(workbook, "御見積書");
         }
         safeRemoveSheet(workbook, "特異事項");
 
diff --git a/src/main/resources/mappers/estimate/estimateMapper.xml b/src/main/resources/mappers/estimate/estimateMapper.xml
index f59e13f8..2e7aaa48 100644
--- a/src/main/resources/mappers/estimate/estimateMapper.xml
+++ b/src/main/resources/mappers/estimate/estimateMapper.xml
@@ -466,7 +466,8 @@
                  GROUP BY CIRCUIT_NO, CIRCUIT_ITEM_ID, CIRCUIT_CFG, CIRCUIT_SUM, PNOW_W
                      )
 
-                SELECT ROUND((SUM(MIN_VALUE) / 1000), 4)  AS CERT_VOL_KW
+                -- 2026-05-22: FLOAT ROUND 결과의 IEEE754 잔여(예: 5.5600000000000005) 차단 위해 DECIMAL(18,4) 캐스팅
+                SELECT CAST(ROUND((SUM(MIN_VALUE) / 1000), 4) AS DECIMAL(18,4))  AS CERT_VOL_KW
                 FROM CIRCUIT_AGG
 
         ]]>
diff --git a/src/main/resources/template/excel/excel_download_quotation_detail_template.xlsx b/src/main/resources/template/excel/excel_download_quotation_detail_template.xlsx
index d976c525..e400eb11 100644
Binary files a/src/main/resources/template/excel/excel_download_quotation_detail_template.xlsx and b/src/main/resources/template/excel/excel_download_quotation_detail_template.xlsx differ
diff --git a/src/main/resources/template/excel/excel_download_quotation_detail_template2.xlsx b/src/main/resources/template/excel/excel_download_quotation_detail_template2.xlsx
index 1ba2927c..18905a50 100644
Binary files a/src/main/resources/template/excel/excel_download_quotation_detail_template2.xlsx and b/src/main/resources/template/excel/excel_download_quotation_detail_template2.xlsx differ